Production of Eastern Gamagrass Accessions Grown under Greenhouse Conditions

The development of adapted acid-tolerant plants is important in the southeastern United States. Eastern gamagrass (Tripsacum dactyloides) is a warm-season perennial native to the Americas, capable of high potential productivity and moderate to high forage quality, for use as grazed or preserved forage. It produces peak growth during hot, dry weather when cool season plants are dormant. Eastern gamagrass has also been reported to penetrate acidic claypan by tolerating low Ca, high Al and low soil pH. As result, eastern gamagrass is being considered as a potential barrier and forage crop in the southeast United States. A study was conducted at the George Washington Carver Agricultural Experiment Station at Tuskegee University, to measure the performance of eastern gamagrass accessions of varying forage potential under greenhouse conditions. Accessions were chosen based on their probable suitability as forage crops, as well as to reflect a broad geographic and genetic spectrum of eastern gamagrass found in the southern US. Single shoots were transplanted and fertilized with 20-20-20 (NPK). After three months of establishment, plants were harvested to 25 cm height every 35 days and forage yield and quality measured. Data on plant height, dry matter yield, and regrowth was recorded. Crude protein, mineral composition, and fiber were used as quality factors. Data indicated that most accessions attained their greatest height at harvest 3. Florida 2 (FL2) produced the tallest plants on average (121.0 cm) prior to the first harvest. Texas 3 (TX3) had the highest daily growth rate before harvest two and produced the tallest plants on average prior to the second harvest (127.8 cm), while TX4 produced the shortest plants on average (95.7 cm). Plant dry weight for the various accessions ranged from 12.0 to 83.5 g/pot while crude protein ranged from 13.7 to 17.3%. These results indicate that the quality of these eastern gamagrass accessions were above the NRC requirements for finishing cattle. A comprehensive review of these eastern gamagrass populations could identify accessions that exhibit specific establishment and growth pattern that are suitable for the southern US.